R34 calculated directly in MAD is very large, about 700 m, therefore threshold is very small.
However, calculation of R34 from the betas and phase advance gives a more sensible value of about 17 m (threshold of about 10 mA). But of course, these numbers should be the same.
Perhaps there is a bug in both MAD and MLC in the calculation of the vertical dispersion, such that errors could be propagated and grow. Need to check this!!!
Tuesday, July 03, 2007
Thursday, June 07, 2007
Beam Loss notes
Beam loss/collimation issues on 4GLS:
1. Parasitic loss should be localised deliberately rather than randomly - so we know where it's going. This appears to be the philosophy of the APS ERL proposal, and the Japanese ERL proposal. http://www.erl07.dl.ac.uk/Tuesday_Presentations/WG_2/Session_1/Xiao-ERL07-3.pdf
although admittedly they are using fewer collimators; but their beam power is about 10x greater (700 MW cf our 55 MW).
Also see:
http://www.aps.anl.gov/News/Conferences/2006/APS_Upgrade/apsmac/Borland_ERLPhysics.pdf
Japanese ERL proposal thinks about localisation too:
http://epaper.kek.jp/fls06/TALKS/WG221_TALK.PDF
but one of the things they are thinking about is trapping of very small losses (in the few Watt level) from gas scattering.
So I think that localisation is a sensible way to go. The collimator length does not depend much on the total power - the collimator lengths is just there to stop the shower coming out the end of the collimator with too high a mean energy. 200 mm Cu is the estimate for 550-750 MeV incident electrons.
2. We are worried about irradiating the undulators, and we have a lot of those. This is what XFEL worry about:
http://flash.desy.de/sites/site_vuvfel/content/e403/e1642/e1849/e1933/infoboxContent2164/TESLA-FEL-2007-051.pdf
(this is a very detailed paper that I have not digested yet!)
But I think at the moment that it is similar in principle to the BESSY-FEL collimation design:
http://web.elettra.trieste.it/fel2004/proceedings/papers/TUPOS02/TUPOS02.PDF
Remember that the beam power in the FELs is much lower than our 55 MW, so we should be as worried about collimation as they are!
3. At the moment, we don't know the best way to detect beam loss. Some issues:
a. Measurement of differential current monitors on the primary beam - I don't think this will be nearly good enough. The S/N isn't good enough - differential measurements are good enough for 'catastrophic' loss over ms, say, but not for ongoing losses.
b. Direct measurement of the loss, via scintillation or other techniques seems like the way to go. e.g. cable-based monitors like those used on ERLP. My favourite at the moment is a 'halo monitor':
c. Measurement of pressure rise sounds good (because it's cheap, and doesn't introduce extra components into the vacuum envelope that cause impedance), but I worry about the timescale of response of things like this, and what happens when they aren't working properly - we have lots of experience of that on the SRS!
d. Similarly, measurements of temperature rise are also not great, because you could for example get a mis-tuning of the beam optics which caused localised beam loss, and then not know about it until it was too late.
For all those reasons, I'm still in favour of collimators that will passively protect the other apertures as much as possible, hence have a fairly dense layout of them (regular spacing in phas advance), and to put monitors in as well.
1. Parasitic loss should be localised deliberately rather than randomly - so we know where it's going. This appears to be the philosophy of the APS ERL proposal, and the Japanese ERL proposal. http://www.erl07.dl.ac.uk/Tuesday_Presentations/WG_2/Session_1/Xiao-ERL07-3.pdf
although admittedly they are using fewer collimators; but their beam power is about 10x greater (700 MW cf our 55 MW).
Also see:
http://www.aps.anl.gov/News/Conferences/2006/APS_Upgrade/apsmac/Borland_ERLPhysics.pdf
Japanese ERL proposal thinks about localisation too:
http://epaper.kek.jp/fls06/TALKS/WG221_TALK.PDF
but one of the things they are thinking about is trapping of very small losses (in the few Watt level) from gas scattering.
So I think that localisation is a sensible way to go. The collimator length does not depend much on the total power - the collimator lengths is just there to stop the shower coming out the end of the collimator with too high a mean energy. 200 mm Cu is the estimate for 550-750 MeV incident electrons.
2. We are worried about irradiating the undulators, and we have a lot of those. This is what XFEL worry about:
http://flash.desy.de/sites/site_vuvfel/content/e403/e1642/e1849/e1933/infoboxContent2164/TESLA-FEL-2007-051.pdf
(this is a very detailed paper that I have not digested yet!)
But I think at the moment that it is similar in principle to the BESSY-FEL collimation design:
http://web.elettra.trieste.it/fel2004/proceedings/papers/TUPOS02/TUPOS02.PDF
Remember that the beam power in the FELs is much lower than our 55 MW, so we should be as worried about collimation as they are!
3. At the moment, we don't know the best way to detect beam loss. Some issues:
a. Measurement of differential current monitors on the primary beam - I don't think this will be nearly good enough. The S/N isn't good enough - differential measurements are good enough for 'catastrophic' loss over ms, say, but not for ongoing losses.
b. Direct measurement of the loss, via scintillation or other techniques seems like the way to go. e.g. cable-based monitors like those used on ERLP. My favourite at the moment is a 'halo monitor':
c. Measurement of pressure rise sounds good (because it's cheap, and doesn't introduce extra components into the vacuum envelope that cause impedance), but I worry about the timescale of response of things like this, and what happens when they aren't working properly - we have lots of experience of that on the SRS!
d. Similarly, measurements of temperature rise are also not great, because you could for example get a mis-tuning of the beam optics which caused localised beam loss, and then not know about it until it was too late.
For all those reasons, I'm still in favour of collimators that will passively protect the other apertures as much as possible, hence have a fairly dense layout of them (regular spacing in phas advance), and to put monitors in as well.
Friday, June 01, 2007
4GLS Phasing Options
Phase 1
Would be low current (good for focus on dynamics expts) and retain some of the combined sources vision. Included is the XUV FEL, the far IR FEL and the spontaneous loop (populated to some level).
There was consensus that completing the HAC loop is a good idea. There are good technical reasons for this relating to the RF. I think it also looks good from a general-project-stance consistency point of view.
Low current in Phase 1 means that fewer IOTs and a smaller cryoplant is needed. Feeling was that we'd buy the rating of IOT and PSUs needed for whole project and use one to power several cavities. When we move to higher power buy more of the units.
A move from three injectors to two injectors was proposed as the spec of the HACL system would cover the requirements of the IR FEL system.
The IR FEL beam would be taken off after Module 1 of the main linac. Need either to schedule operation of spontaneous loop and Far IR FEL at different times or use a kicker of some sort (not felt to be tricky at rep rates condidering).
A move from two upstream arcs to one upstream arc was proposed. There's then a requirement to split the XUV-FEL beam from the HACL beam. At the lower rep rates proposed in Phase 1 this is technically feasble with current technology.
Could phase the development of the XUV FEL, e.g. 6/8-40eV first and then 35-100eV. Might not need to do this.
For the discussion the current in the spontaneous loop was 0.3 mA (4.3MHz at 77pC). There was no real discussion of 13MHz at 200 pC (which of course gives 2.6 mA).
I've tried to capture some of the machine implications on the attached powerpoint file. I've not messed with the HACL though.
Phase 2
Would be high current in the spontaneous loop, the VUV FEL, further IR FEL development, further population of the spontaneous sources.
Need to mesh R&D roadmap with injector development.
More IOTs needed and cryo plant needs uprating.
R&D development on kickers permits a single upstream arc and kicker otherwise a second upstream arc needed. Again need to mesh with the R&D roadmap.
VUV FEL incorporated.
Need a set of milestones for eventual delivery of 100mA
Lia will be producing a document on the global view of R&D needed for ERLs with timeline as an output of ERL07.
Clearly the costing matrix would need to capture phasing of the RF and cryo, have the costs for XUV FELs separate, have the cost for the FAR IR photoinjector and FELs separate.
Hope this is clear, it's not that easy to summarise!
Would be low current (good for focus on dynamics expts) and retain some of the combined sources vision. Included is the XUV FEL, the far IR FEL and the spontaneous loop (populated to some level).
There was consensus that completing the HAC loop is a good idea. There are good technical reasons for this relating to the RF. I think it also looks good from a general-project-stance consistency point of view.
Low current in Phase 1 means that fewer IOTs and a smaller cryoplant is needed. Feeling was that we'd buy the rating of IOT and PSUs needed for whole project and use one to power several cavities. When we move to higher power buy more of the units.
A move from three injectors to two injectors was proposed as the spec of the HACL system would cover the requirements of the IR FEL system.
The IR FEL beam would be taken off after Module 1 of the main linac. Need either to schedule operation of spontaneous loop and Far IR FEL at different times or use a kicker of some sort (not felt to be tricky at rep rates condidering).
A move from two upstream arcs to one upstream arc was proposed. There's then a requirement to split the XUV-FEL beam from the HACL beam. At the lower rep rates proposed in Phase 1 this is technically feasble with current technology.
Could phase the development of the XUV FEL, e.g. 6/8-40eV first and then 35-100eV. Might not need to do this.
For the discussion the current in the spontaneous loop was 0.3 mA (4.3MHz at 77pC). There was no real discussion of 13MHz at 200 pC (which of course gives 2.6 mA).
I've tried to capture some of the machine implications on the attached powerpoint file. I've not messed with the HACL though.
Phase 2
Would be high current in the spontaneous loop, the VUV FEL, further IR FEL development, further population of the spontaneous sources.
Need to mesh R&D roadmap with injector development.
More IOTs needed and cryo plant needs uprating.
R&D development on kickers permits a single upstream arc and kicker otherwise a second upstream arc needed. Again need to mesh with the R&D roadmap.
VUV FEL incorporated.
Need a set of milestones for eventual delivery of 100mA
Lia will be producing a document on the global view of R&D needed for ERLs with timeline as an output of ERL07.
Clearly the costing matrix would need to capture phasing of the RF and cryo, have the costs for XUV FELs separate, have the cost for the FAR IR photoinjector and FELs separate.
Hope this is clear, it's not that easy to summarise!
Tuesday, May 22, 2007
ERL07 WG2 Session 2 - Notes
Sakanaka - Ion Trapping
Use kicker to kick out parts of the injector beam - needs fast kicker (1.3 GHz bunch separation), and get ringing. Maybe can avoid ringing by using two kickers Pi out of phase.
Methods to avoid trapping:
1. Gaps - match beam loading in main linac, and use feed-forward RF in injector
2. Beam blow-up - no beam loading in injector, but the fact there is still focusing term from the blown-up bunches mean that the effect on clearing is less good.
3. Moving the beam - 'beam shaking'. Not viewed as a good thing - tends to hits resonances .
Nakamura -Resistive-Wall Beam Breakup
PRST-AB 7, 034402 (2004)
Transverse wakefield can give break-up.
Use kicker to kick out parts of the injector beam - needs fast kicker (1.3 GHz bunch separation), and get ringing. Maybe can avoid ringing by using two kickers Pi out of phase.
Methods to avoid trapping:
1. Gaps - match beam loading in main linac, and use feed-forward RF in injector
2. Beam blow-up - no beam loading in injector, but the fact there is still focusing term from the blown-up bunches mean that the effect on clearing is less good.
3. Moving the beam - 'beam shaking'. Not viewed as a good thing - tends to hits resonances .
Nakamura -Resistive-Wall Beam Breakup
PRST-AB 7, 034402 (2004)
Transverse wakefield can give break-up.
ERL 07 Workshop Notes - Session 1
Michael Borland - Touschek Scattering
Beam-loss mechanisms fall into two classes:
1. Low-energy, unpredictable - collimate at low energy
2. Calculable, e.g. Touschek and Nonlinear Optics
Touschek dominates CW beam loss in low emittance rings. Probably then significant in ERL light source. Touschek is well-studied in rings, but not studied in single-pass accelerators.
Assume gas scattering is smaller than Touschek - at about 1 nTorr.
ERL electron cooler - 5 nC per bunch, 4 um emittance (100 ps bunch length). ERL beam cools both directions. 54 MeV bunches travel 100 m down ERL cooling line - some space charge acting. Will compensate space charge using weak solenoids every 10 m.
3rd-harmonic cavity is used to flatten energy gain of the very long (100 ps) bunch so that energy spread is small enough (4.10^-4 rather than few 10^-3 without 3rd-harmonic)
BBU threshold is high with the small number of cavities and modelled HOMs.
Have a dog-leg which moves the beam H and V at the same time (5 quads for dispersion matching). No perceived issue with space charge at the centre of the dog-leg quad.
300 m turnaround for the beam path.
Accumulation of ions will be only in the turnaround - the cooling region has a big ion beam which will repel the ions in that 100m section.
Path length correction is mechanical - move the arc.
Amplitude stability is 10^-4 in RF - should be good enough.
Beam-loss mechanisms fall into two classes:
1. Low-energy, unpredictable - collimate at low energy
2. Calculable, e.g. Touschek and Nonlinear Optics
Touschek dominates CW beam loss in low emittance rings. Probably then significant in ERL light source. Touschek is well-studied in rings, but not studied in single-pass accelerators.
Assume gas scattering is smaller than Touschek - at about 1 nTorr.
ERL electron cooler - 5 nC per bunch, 4 um emittance (100 ps bunch length). ERL beam cools both directions. 54 MeV bunches travel 100 m down ERL cooling line - some space charge acting. Will compensate space charge using weak solenoids every 10 m.
3rd-harmonic cavity is used to flatten energy gain of the very long (100 ps) bunch so that energy spread is small enough (4.10^-4 rather than few 10^-3 without 3rd-harmonic)
BBU threshold is high with the small number of cavities and modelled HOMs.
Have a dog-leg which moves the beam H and V at the same time (5 quads for dispersion matching). No perceived issue with space charge at the centre of the dog-leg quad.
300 m turnaround for the beam path.
Accumulation of ions will be only in the turnaround - the cooling region has a big ion beam which will repel the ions in that 100m section.
Path length correction is mechanical - move the arc.
Amplitude stability is 10^-4 in RF - should be good enough.
Monday, May 14, 2007
4GLS Diagnostics Discussion Meeting, 14th May 2007
CDR design has obviously changed, but the diagnostic principles haven't changed. The
HACL Gun:
Gun energy - temp diagnostics line
Gun emittance - temp diagnostics line
Cathode emitted bunch length
Issues of run-up from low current to high current
(separate meeting!)
Assume built gun (check Cornell prototype): current measurements, beam centroid measurements, beam profile measurements, insertable screen/Fcup?
Interlocking issue - make sure screens don't go in at high current.
HACL Injector:
Output energy, chirp, bunch length - phase/voltage measurement of each cavity
Tranverse phase space measurement? May be a 'wish-list item.
Boris/Rob/Julian/Hywel to look at essential measurements
XUV Injector:
Collaboration with PITZ?
Fast amplitude stabilisation of RF amplitude and phase during 20 us RF pulse in XUV injector.
Output energy, chirp, bunch length - phase/voltage measurement of each cavity
Tranverse phase space measurement? May be a 'wish-list' item.
Include BC1 setup
Main Linac:
HACL team - measurements list: (Hywel)/Bruno/Rob/Alex
Need to think about the modes we will be running in:
XUV only: 1nC at 1kHz
HACL only: low current/high current/
XUV/HACL only:
Transfer matrix measurements - are they needed?
Energy Recovery/Dump
Measurement of energy recovery efficiency. Measurement of loss at level required?
HACL and IDs
Modes for commissioning again.
Profile monitors - low current with screens only, high current with alternative monitor - are they needed?
Tomography measurement - SR output resolution vs. resolution of other instruments for measuring of transverse profile, e.g. wavelength, diffraction etc.,
THz measurement in straight 1?
Streak cameras at short bunch length - 100 fs resolution under development, 10 fs
EO does not work at high current, use streak cameras at high current in upstream regions of the HACL ID arc.
How do we get the VUV-FEL to work? Bunch length, time overlap,
Discussion: Hywel/Frances/Neil
XUV-FEL
Emittance measurement is under control (Bruno!)
Seed laser diagnostics
Discussion
Neil/Steve/Frances/Bruno/Brian Sheehy/Graeme
IR-FEL:
Establish group: Boris/Bruno/Neil
HACL Gun:
Gun energy - temp diagnostics line
Gun emittance - temp diagnostics line
Cathode emitted bunch length
Issues of run-up from low current to high current
(separate meeting!)
Assume built gun (check Cornell prototype): current measurements, beam centroid measurements, beam profile measurements, insertable screen/Fcup?
Interlocking issue - make sure screens don't go in at high current.
HACL Injector:
Output energy, chirp, bunch length - phase/voltage measurement of each cavity
Tranverse phase space measurement? May be a 'wish-list item.
Boris/Rob/Julian/Hywel to look at essential measurements
XUV Injector:
Collaboration with PITZ?
Fast amplitude stabilisation of RF amplitude and phase during 20 us RF pulse in XUV injector.
Output energy, chirp, bunch length - phase/voltage measurement of each cavity
Tranverse phase space measurement? May be a 'wish-list' item.
Include BC1 setup
Main Linac:
HACL team - measurements list: (Hywel)/Bruno/Rob/Alex
Need to think about the modes we will be running in:
XUV only: 1nC at 1kHz
HACL only: low current/high current/
XUV/HACL only:
Transfer matrix measurements - are they needed?
Energy Recovery/Dump
Measurement of energy recovery efficiency. Measurement of loss at level required?
HACL and IDs
Modes for commissioning again.
Profile monitors - low current with screens only, high current with alternative monitor - are they needed?
Tomography measurement - SR output resolution vs. resolution of other instruments for measuring of transverse profile, e.g. wavelength, diffraction etc.,
THz measurement in straight 1?
Streak cameras at short bunch length - 100 fs resolution under development, 10 fs
EO does not work at high current, use streak cameras at high current in upstream regions of the HACL ID arc.
How do we get the VUV-FEL to work? Bunch length, time overlap,
Discussion: Hywel/Frances/Neil
XUV-FEL
Emittance measurement is under control (Bruno!)
Seed laser diagnostics
Discussion
Neil/Steve/Frances/Bruno/Brian Sheehy/Graeme
IR-FEL:
Establish group: Boris/Bruno/Neil
Friday, May 04, 2007
4GLS Beam Loss initial brainstorm - 4th May 2007
Machine protection system has to be designed - we need to consider all likely eventualities.
General considerations: some diagnostics will cause loss (e.g. running into an FCup), so we will need different operating modes to allow this.
As with other facilities, we will need an interlock system
We need to obtain a time constant for the cryomodules - how long will they ring if the power goes off? About 0.1ms
Machine protection scales:
30-300 ns is as fast as signals can travel through the 4GLS; machine protection can't go as fast as this.
Typical switch off in machine protection is 10s of us (check).
Vacuum faults:
Slow leak - Gas bremsstrahlung (radiation monitors), ion trapping change (how much?), linac ices up,
Fast leak - triggers gate valve - need to turn off electrons before valve shuts. What happens if a gate valve shuts by itself? This is probably standard accelerator technology, but the beam power is very high in our case. e.g. 5 kJ can hit a faulty valve in 0.1 ms if the electrons are not turned off! Same goes for diagnostics, e.g. screens.
HACL:
Cathode:
Long time constant change (QE change)
Laser shut-off - probably not a problem as there are no electrons
Laser loses sync with RF system (outside bucket) - bunch is at different phase, so is bunched differently and comes out with different energy from injector. How fast can that happen?
VUV-FEL mode: low rep rate selected. Can the laser go CW (chopper fails)? How will the chopper work?
other failure modes of the laser/cathode?
Gun:
HV PSU trip-off (low SF6, PS fault) - injector energy will reduce over a time until we can trip off the laser. Particles will go in the wrong direction in BC1 - need to collimate?
HV PSU set wrong - what happens if we are mis-tuned, and how do protect against it?
Buncher:
Fails, beam is not bunched - what happens? Energy spread and length growth - will this be beyond
Buncher works at the wrong phase? Can the acceleration produced be significant
HACL Modules:
Modules at wrong phase
Wrong voltage - probably be to reduce the voltage
Everything here has a time constant
RF control fault - e.g. missing bunches or pulses - gives transient beam-loading
BTS:
Magnet failure:
Wrong setting/Trip - may for example have to arrange that inductance of magnets is high to make their intrinsic turn-off slow. May get this for free...
Some magnets are more critical than others (e.g. the ones upstream of the main linac)
Collimators are in the HACL arcs to take a short pulse of errant beam, and also to catch halo; main linac can easily change in 0.1ms.
Magnet failure can cause path length change - need to check how big this change can be.
Magnet failure can cause beam movement which can hit the IDs - need to do something similar to what we did for the SRS and DIAMOND, e.g. ray-tracing of possible beam routes through the IDs.
Main Linac:
Check - ILC linac failure modes.
VUV-FEL:
Lasing goes on and off - should be no problem as unlased energy range lies within lased energy range.
Steering from misaligned/faulty magnet arrays - can't go too fast, should be able to be
PLC:
PLC moves or there is a magnet failure - energy recovery is lost. Linac will pick this up.
Dump:
Energy too high - power load too high, irradiation. Beam can also hit crotch and spreader.
Energy too low - absorption depth in dump will be less.
Raster magnets fail - need to independently sense the raster scan failure, as there will be lots of radiation/signal in this part of the machine.
XUV-FEL:
Gun/Injector:
Missed pulses can occur - probably doesn't matter if there are no pulses, e.g. in main linac.
Overpulses (e.g. extra laser pulses) - then get extra electrons that are not being accelerated. Depends on the length of the RF pulse.
Linac:
Wrong relative phase of XUV and HACL bunches. Can the HACL bunches 'push' the linac phase around enough to change the XUV gun phase.
HHG laser can melt something directly?
General considerations: some diagnostics will cause loss (e.g. running into an FCup), so we will need different operating modes to allow this.
As with other facilities, we will need an interlock system
We need to obtain a time constant for the cryomodules - how long will they ring if the power goes off? About 0.1ms
Machine protection scales:
30-300 ns is as fast as signals can travel through the 4GLS; machine protection can't go as fast as this.
Typical switch off in machine protection is 10s of us (check).
Vacuum faults:
Slow leak - Gas bremsstrahlung (radiation monitors), ion trapping change (how much?), linac ices up,
Fast leak - triggers gate valve - need to turn off electrons before valve shuts. What happens if a gate valve shuts by itself? This is probably standard accelerator technology, but the beam power is very high in our case. e.g. 5 kJ can hit a faulty valve in 0.1 ms if the electrons are not turned off! Same goes for diagnostics, e.g. screens.
HACL:
Cathode:
Long time constant change (QE change)
Laser shut-off - probably not a problem as there are no electrons
Laser loses sync with RF system (outside bucket) - bunch is at different phase, so is bunched differently and comes out with different energy from injector. How fast can that happen?
VUV-FEL mode: low rep rate selected. Can the laser go CW (chopper fails)? How will the chopper work?
other failure modes of the laser/cathode?
Gun:
HV PSU trip-off (low SF6, PS fault) - injector energy will reduce over a time until we can trip off the laser. Particles will go in the wrong direction in BC1 - need to collimate?
HV PSU set wrong - what happens if we are mis-tuned, and how do protect against it?
Buncher:
Fails, beam is not bunched - what happens? Energy spread and length growth - will this be beyond
Buncher works at the wrong phase? Can the acceleration produced be significant
HACL Modules:
Modules at wrong phase
Wrong voltage - probably be to reduce the voltage
Everything here has a time constant
RF control fault - e.g. missing bunches or pulses - gives transient beam-loading
BTS:
Magnet failure:
Wrong setting/Trip - may for example have to arrange that inductance of magnets is high to make their intrinsic turn-off slow. May get this for free...
Some magnets are more critical than others (e.g. the ones upstream of the main linac)
Collimators are in the HACL arcs to take a short pulse of errant beam, and also to catch halo; main linac can easily change in 0.1ms.
Magnet failure can cause path length change - need to check how big this change can be.
Magnet failure can cause beam movement which can hit the IDs - need to do something similar to what we did for the SRS and DIAMOND, e.g. ray-tracing of possible beam routes through the IDs.
Main Linac:
Check - ILC linac failure modes.
VUV-FEL:
Lasing goes on and off - should be no problem as unlased energy range lies within lased energy range.
Steering from misaligned/faulty magnet arrays - can't go too fast, should be able to be
PLC:
PLC moves or there is a magnet failure - energy recovery is lost. Linac will pick this up.
Dump:
Energy too high - power load too high, irradiation. Beam can also hit crotch and spreader.
Energy too low - absorption depth in dump will be less.
Raster magnets fail - need to independently sense the raster scan failure, as there will be lots of radiation/signal in this part of the machine.
XUV-FEL:
Gun/Injector:
Missed pulses can occur - probably doesn't matter if there are no pulses, e.g. in main linac.
Overpulses (e.g. extra laser pulses) - then get extra electrons that are not being accelerated. Depends on the length of the RF pulse.
Linac:
Wrong relative phase of XUV and HACL bunches. Can the HACL bunches 'push' the linac phase around enough to change the XUV gun phase.
HHG laser can melt something directly?
Tuesday, May 01, 2007
Friday, April 27, 2007
CICT/CI/ASTeC Support Meeting, 27th April 2007
Notes and Actions:
1. IT Services
PC Support is now called DL IT Support - now in Canal View
No longer particular support hours. Emails now going to Footprints helpdesk support.
New support address: dlitsupport'at'dl.ac.uk
New support website: http://itservices.dl.ac.uk/ - an excellent step forward.
3rd-party access forms - have been updated on the website for now. Some changes will be made, and a web form will be made.
Campus IT may be put out to tender (bad idea). DL would like to do it.
2. Outgoing CI email addresses. Can be done (e.g. Swapan's email address), but will be done on an individual-by-individual basis on request.
3. PPD files - to go onto IT support website http://itservices.dl.ac.uk/printing/printing3.htm. Chris and Hywel to list out printers post-meeting.
4. POPmail instructions. These work, and will be put onto the IT Services website.
5. Backups - We have bought 2 legato licenses. They haven't arrived yet.
6. apsv5 still not working - C.Dean still looking at it. The machine may have to be sent back to Dell.
7. New CI website - Barbara Runcie will be the webmaster.
Design produced in a couple of weeks.
Agree design with Swapan.
Migrate existing content to new design (Barbara/Stuart)
Migrate to Rythmix and updates done by Barbara. Updates by e.g. Liz to be explored.
8. ASTeC/CI website interaction - meeting with Swapan and Mike P. to find out what they want. (Action HLO)
9. C.Dean to upgrade Plone version projects.astec.ac.uk/ (lowish priority).
1. IT Services
PC Support is now called DL IT Support - now in Canal View
No longer particular support hours. Emails now going to Footprints helpdesk support.
New support address: dlitsupport'at'dl.ac.uk
New support website: http://itservices.dl.ac.uk/ - an excellent step forward.
3rd-party access forms - have been updated on the website for now. Some changes will be made, and a web form will be made.
Campus IT may be put out to tender (bad idea). DL would like to do it.
2. Outgoing CI email addresses. Can be done (e.g. Swapan's email address), but will be done on an individual-by-individual basis on request.
3. PPD files - to go onto IT support website http://itservices.dl.ac.uk/printing/printing3.htm. Chris and Hywel to list out printers post-meeting.
4. POPmail instructions. These work, and will be put onto the IT Services website.
5. Backups - We have bought 2 legato licenses. They haven't arrived yet.
6. apsv5 still not working - C.Dean still looking at it. The machine may have to be sent back to Dell.
7. New CI website - Barbara Runcie will be the webmaster.
Design produced in a couple of weeks.
Agree design with Swapan.
Migrate existing content to new design (Barbara/Stuart)
Migrate to Rythmix and updates done by Barbara. Updates by e.g. Liz to be explored.
8. ASTeC/CI website interaction - meeting with Swapan and Mike P. to find out what they want. (Action HLO)
9. C.Dean to upgrade Plone version projects.astec.ac.uk/ (lowish priority).
Thursday, April 26, 2007
Seminar 26th April - Sergiy Khodyachykh, PITZ Diagnostics
Tomography uses MENT algorithm (Maximum ENTropy) to reconstruct the phase space in a 4-screen FODO channel.
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